Abstract: The leads to a heater for an electrothermal hydrazine monopropellant thruster comprise tungsten conductors wrapped with smaller diameter tungsten support wire and insulated with beads of alumina (Al.sub.2 O.sub.3). A transition section connects the leads to regular leads. An attaching support wire is attached to the heater at one end and to the transition section at the other end. The insulated conductors and attaching wire are wrapped together with nickel ribbon to form a sheath.

Abstract: A unitary integral electrically heated nozzle device for plastic molding or die casting equipment which has a novel casing integral with a heater core, which is insulated to prevent conduction of electricity and loss of thermal transmission to the casing, the electrical insulation being compacted within the casing and around the heater core and the assembly being sealed and swaged into a unitary form, said device being structured to heat the area of a gate or passage for delivery of molten material into a forming cavity. The nozzle device may be shaped, and the nozzle systems include such nozzle devices in the gate channels for delivering molten material to the forming cavity.

Abstract: An electrical heating unit of a heating set for hair curling rollers, is composed of two aluminum sheet components carrying together three parallel rows of upstanding heating posts and enclosing between them a resistance heater of the "rope heater" kind. It comprises a main plate of rectangular configuration which contains two lateral parallel rows of hollow heating posts along the long edges of the rectangle and is centrally recessed over its entire length in the shape of a rectangular trough of a depth corresponding to the thickness of the rope heater. The rope heater is positioned in the trough and extends along the four sides of the rectangle, while its ends are attached to a thermostatic switch and a thermo-fuse located in a separate pocket in this trough. A top plate covers the trough in the main plate and is provided with one central row of heating posts which are staggered in relation to the posts of the lateral rows.

Abstract: An electric heater for heating oil contained in the sump well of a compressor includes a thermally conductive shell having first and second opposed inner surfaces. A ceramic core having a D-shaped cross-section throughout is positioned in the shell and is provided with longitudinal channels which are disposed substantially the same distance from the outer curved surface of core. An electric resistance heating element is disposed in the channels and is energizable by a source of power for developing heat under the control of a thermostat disposed in the shell. A resilient pad of ceramic fiberglass material having low thermal conductivity is disposed between the flat surface of the core and the thermostat and urges the curved surface of the core and the thermostat into contact with the opposed inner surfaces of the shell while substantially blocking heat transfer therethrough from the heating element to the thermostat.

Abstract: A glow plug for use in a diesel engine comprises first and second helical heaters covered with a sheath. The second heater is made of material having larger resistance temperature coefficient than that of the first heater. A gap larger than winding pitches of the two heaters is provided there between and the two heaters are electrically interconnected in the gap.

Abstract: An improved glow plug (10) which is adapted to be continuously electrically heated to a preselected elevated temperature in order to ignite relatively lower-cetane-number alternative fuels. The glow plug (10) includes a ceramic surface ignition element (20) disposed substantially externally of the glow plug body (18) and means (24) for permitting thermal expansion and contraction of the ignition element (20) while maintaining continuous electrically-conductable and gas-impermeable contact between the ignition element (20) and the glow plug body (18).

Abstract: A ceramic heating element is held in a metal housing to be mounted on an internal combustion engine, so that the heating element is operated as a glow plug for igniting an air-fuel mixture. The ceramic heating element is formed of an electrode section housed in the housing and a heat generating section extending out of the housing, whereby the heat generating section is exposed to the mixture in an engine cylinder. The electrode and heat generating sections are divided into two portions, respectively, and both forward ends of divided heat generating portions are connected with each other, so that electric current flows from one of the electrode portions through the divided heat generating portions to the other electrode portion.

Abstract: The electric heater herein disclosed is particularly adapted to heat a fluid and to provide a broad, substantially flat heater surface exposed to the fluid to be heated. The heating element is well adapted for deep fat frying use in that it is of high voltage and is economical to manufacture. The invention makes use of standard elongated, tubular, metal-sheathed heaters which are produced in large quantities for a multitude of uses. Such elements are slid into a metal tube of selected diameter and wall thickness, and the assembly is flat-pressed in appropriate sections with the ends round for termination with such fittings as are required. The assembly may then be bent to produce a desired configuration.

Abstract: A heat exchange assembly for raising a process fluid, such as ultra-pure, de-ionized water, to an elevated temperature without adversely affecting the quality thereof includes coaxially-arranged inner and outer pipes, the annular space therebetween defining a flow passage for the fluid to be heated. The inner pipe is formed of high-strength metal of good thermal conductivity and encloses a heat source, such as steam, circulating heated fluid or an electric heater. The inner pipe is ensheathed by an extruded heat-shrinkable plastic tube of non-reactive material, such as PTFE or polypropylene not exceeding 7 mils in thickness, which is shrunk-fit thereon to form one wall of the flow passage. The opposing wall of the passage is formed by the interior surface of the outer pipe which is also constituted by non-reactive plastic material such as PTFE or polypropylene.

Abstract: This invention relates to a spacer clip for an injection molding electric heating element. A number of clips, each formed of a continuous band, are slipped over one end of the heating element and slid along to predetermined positions. Each clip is then crimped to the heating element in that position which forms a finger which extends radially from the heating element in a predetermined orientation. The heating element with the spacer clips attached is located in a suitable mold for casting and the fingers of the clips locate each coil of the element with sufficient clearance from the mold and the other coils. The thickness of the conductive heater cast around the heating element is important to provide uniform heat transfer. The spacer clips are formed of a material such as stainless steel which has sufficient pliability to be securely crimped to the heating element, but sufficient strength to reliably retain the heating element in position.

Abstract: An apparatus for heating liquid in a pipe to prevent freezing of the liquid and for de-icing of frozen pipes includes an elongated housing constructed of plastic material and having a central bore and fittings for detachably coupling each end of the housing to the open end of a liquid pipe so that the central bore connects a first liquid pipe to a second liquid pipe. The fittings each comprise a sleeve attachable to the pipe end, a sealing gasket between the end of the housing and an annular flange on the sleeve, and a threaded coupling nut cooperating with external threads on the housing and having a flange engaging the sleeve flange. The housing includes a lateral passageway intermediate its end communicating with the central bore and closed by a sealer valve having an opening with a normally closed penetrable seal of elastomeric material.

Abstract: Water degasification and distillation apparatus having a container for water to be degasified and distilled, a relatively small boiler adjoining said container and having a first conduit extending into the container so that a selected water level in the container will fill said boiler to a selected height, a condenser within the container and immersed in the water contained therein, a second conduit extending from the space above the water in said boiler to the inlet of the condenser, an outlet on the condenser extending through a container wall for discharging degasified and distilled water and heating means in said boiler for heating the water therein at a rate greater than the capacity of the second conduit to handle the steam generated in the boiler.

Abstract: The heating element has an outer connector assembly including a cylindrical threaded portion adapted to be threaded into a boss on the heater water tank and a sheathed continuous electric resistance heating rod which has both ends secured to the connector assembly and which extends generally perpendicular to the heater tank centerline when installed. The heating rod is formed in a serpentine, generally W-shaped pattern with respect to the centerline of the cylindrical threaded portion, which provides the heating rod with an effective length greater than the inside diameter of the water tank, permits the heating rod to be inserted and withdrawn through the bore of the tank boss and permits the heater rod to be rotated, as the connector assembly is being threaded into and out of the tank boss, without striking any obstructions inside the water tank, such as the cold water dip tube, the hot water pipe and the anticorrosion anode.

Abstract: An electric heater, especially for small electric appliances, such as hair roller heaters, egg boilers, or the like, and a method of making same utilizes at least one heating element having contact-making zones on opposite planar parallel surfaces thereof, electrical connection elements in the form of essentially planar contact plates, a contact plate being placed on each of the opposite surfaces, and a holding member having a heat conducting, electrical insulating layer upon a surface thereof. The holding member is bent into a U-shape so as to hold the contact plates clamped fast to the heating elements between legs of the U-shape of the holding member and with the insulating layer disposed on an inner surface of the U-shape between the plates and holding member. In accordance with a preferred embodiment, the insulating layer is of a resilient material having a heat-conductive additive distributed therethrough and the heating elements are formed of PTC material.

Abstract: A fuel tank is provided with an electric immersion heating element assembly directly immersible in the fuel within the tank and resting on the curved tank bottom. The assembly includes an elongated, cylindrically shaped, solid aluminum heater body having a longitudinally extending cavity in each end thereof closed by a resilient plastic end cap of larger diameter than the body and secured thereto by a snap fit rib and groove connection. One of the cavities has an inward axial extension in which is received an electric heating element with one end of the heating element electrically connected to the body at the inner end of the extension. An adjustable thermostatic switch is located in the other cavity and is electrically connected in series with the other end of the heating element and with one wire of a flexible power supply conduit extending in sealed relation through the end cap closing the other cavity.

Abstract: A glow-plug ignitor for diesel engines and the like, comprising a tubular body having external screw threads and an adjoining hexagonal formation by which a tool such as a wrench can be applied to the body to screw it into the threaded cavity of a cylinder. Next to the hexagonal formation is a spade lug connector for bringing current to the plug, the connector being so arranged as to permit the application of either a socket-type wrench or else a box-end wrench. The inner end of the body has an elongate projecting pin on which there is a tightly wound resistance coil that becomes incandescent when excited with the proper electric current. The valleys of the coil show higher temperatures, for a given heating current, due to the radiation and reception of radiated heat involving the opposed surfaces; therefore, starts at lower engine temperatures are improved.

Abstract: A planar heat generating device is made up of two heat radiating plates having through-holes, heat generating units of positive temperature characteristic material held between the two plates, two lead wires connected to the two plates, and an insulating cover layer of heat resisting synthetic resin which covers the two plates, the heat generating units and the connecting points of the lead wires. Fluid through-holes are formed in the parts of the insulating cover layer which are applied to the through-holes of the plates, so that the heat generated is effectively conducted to the fluid.

Abstract: An electric immersion heater for use in conjunction with tanks made by different manufacturers. The tanks are typically cylindrical and include an annular mounting flange at the upper open end provided with a specific arrangement of mounting apertures receiving fasteners connecting the heater mounting flange to the tank. Tank mounting flanges of different manufacturers use different number of fasteners and this presents a problem in that, unless an adaptor of some kind is used, an immersion heater must be provided with a special flange with mounting apertures matching the tank apertures for the fasteners.The immersion heater is provided with a mounting flange having an arrangement of mounting apertures which permits the heater to be used with tanks with mounting flanges having different mounting aperture arrangements without the necessity of adaptors or special flange arrangements.

Abstract: A preheater for a casting ladle includes a stationary horizontal refractory deck having vertical apertures in which are disposed refractory plugs, each of which supports an electrical heating element that depends downwardly from the refractory deck. A lifting table is movable into registration with the set of depending electrical heating elements and is also adapted to support the casting ladle thereon and to raise it into surrounding relation with the electric heating elements that depend from the refractory deck. Individual defective heating elements can be removed and replaced during operation of other operative heating elements.

Abstract: A continuous flexible cable heater having a coil continuous conductor in a plastic casing. The conductor has uncoiled regions spaced therealong between coiled regions to permit bending at a radius less than twice the jacket outside diameter. A heater assembly has the cable disposed on a support in closely folded serpentine planar array. A sensor portion of the continuous cable is folded over and adjacent the upper surface of the planar array and includes fusible protective means to cut off the heater in the event of overheating of the liquid or excess current draw.

Abstract: A heater for heating liquids such as water in an aquarium comprises a water-impermeable housing including a heating section for immersion in the water. Within the heating section of the housing is a flexible, distributed planar heating element. The housing is resistant to breakage from mechanical and operating abuse and has a high heat transfer coefficient and high heat distortion temperature. To prevent the housing from melting when a control element of the heater malfunctions, preferably the aquarium heater includes temperature limiting means such as a circuit protection element comprising a material having a positive temperature coefficient of resistance. Preferably, the heating section of the housing is fabricated with large surface area walls to accommodate the planar heating element, and is provided with coupling means for maintaining the heating element thermally coupled to the walls of the heating section.

Abstract: An immersible heater for an aquarium includes a waterproof, heat-resisting, flat plastic case which is tripartitioned in its interior, one chamber holding a flat coil carrier bonded or welded to the case; an upper chamber contains a leaf spring actuated by a bimetallic element; these chambers are separated by a thermally isolating chamber. The bias of the bimetallic actuator is adjusted by a sealed feedthrough screw. Current flow through the heating coil is indicated by a lamp covered with a thinner wall portion of the case. The front of the case carries heat-dissipating and -stiffening ribs; the rear of the case carries suction cups.

Abstract: This invention relates to an integral heated probe for plastic injection molding and a method of making the same. The probe has an elongated steel outer body with a cylindrical well extending to a pointed tip end. An electrical cartridge heater member positioned in the well with the leads extending out the open end. The space adjacent the pointed tip end and all around the cartridge heater is filled with copper to improve heat transfer between the heater member and the outer body. The copper fusing is performed by two-stage heating in a vacuum furnace. First a slug of copper is inserted into the well and heated to melt it into the pointed tip end. Then the heater member is inserted into the well through a sleeve of copper at the top and heated to melt the copper. The copper flows down around the heater member and fuses to it, the outer body and the previously inserted copper.

Abstract: A diesel fuel tank has an opening in the top wall through which an electric immersion heater assembly is inserted into the tank to heat the contents thereof. The immersion heater assembly includes an outer tubular member arranged vertically in the tank and having an open upper end sealingly secured in the tank opening and a closed lower end near the bottom of the tank. An inner tubular member of slightly smaller diameter than the outer member and of a length coextensive with a major portion of the length of the outer member is removably inserted into the outer member through the open end thereof. A double filament DC light bulb mounted on the lower end of the inner member serves as an electric heating element located in the lower portion of the outer member. Air heated by the light bulb flows upwardly by convection into the narrow circumferential space between the inner and outer members thereby assuring that the entire length of the outer member in contact with the diesel fuel in the tank is heated.

Abstract: A nozzle for use in an injection molding machine. The nozzle comprises a tripartite body having an inlet, an outlet and an interconnected passageway extending therethrough. A heat pipe is located within the center of the body and portions of the passageway are disposed about the heat pipe. A resistance heating band is mounted on the body to conduct heat therethrough to heat the heat pipe. The heat pipe serves to heat plastic flowing through the surrounding passageway portions to the outlet.

Abstract: A burner assembly (18) for heating the intake air of an internal combustion engine (2) including a burner housing (32) containing a fuel passage (52, 66, 70, 72) and a glow plug (87) for heating the burner housing (32) upon start up of the burner to melt fuel wax deposits in the fuel passage (52, 66, 70, 72). The glow plug (87) includes a metal sheath (88) designed normally to contact air when energized at a rated level. The burner housing (32) includes a cavity (86) shaped to receive the glow plug (87) with a minimal clearance (a) large enough to prevent interference during assembly but small enough to allow metal-to-metal heat transfer into the housing (32) when the glow plug (87) is energized at twice its rated level.

Abstract: A heater plug comprising a heater coil connected to a terminal pin, said terminal pin maintained in gas-tight manner at least in part within and insulated from a plug shell, at least the surface of said heater coil formed by a metal or a base alloy of a metal of the platinum group said heater coil supported by heat electrically insulating rod-like or tubular supporting body heater coil surrounded by a protective tube.The heater plug is useful as a starting aid for diesel engines and other internal combustion engines, especially those without spark ignitions.

Abstract: A preheater is disclosed which can be inserted and withdrawn from a well tube defining a curved passage, without having its heating element damaged, by utilizing the flexibility of a spirally coiled structure having increased stability of shape and excellent capacity of restoring its original shape after elastic deformation.

Abstract: A cartridge-type electric immersion heating element having an integrally contained, self-limiting thermostatic control included in its electrical circuit includes an electric resistance heating element embedded in compacted powdered insulating material partially filling a tubular metallic sheath open at one end. A preset thermostat is located within a thermostat sleeve positioned in close proximity with the sheath wall and has an end embedded in the insulating material. The thermostat is connected in series circuit with the heating element and the ends of power supply leads enter the sheath through the open end thereof. A body of potting compound, such as epoxy resin, completely fills the remainder of the sheath, seals the open end thereof and encapsulates the other end of the sleeve and the power supply lead ends whereby the sleeve and thermostat are securely held in position in the sheath.

Abstract: An electric water heater of the "instantaneous" type heats the water immediately before use as the water flows through a closed small volume container having a water inlet and a water outlet. An electric high wattage immersion heating element in the container is in circuit with a protective thermal cut-out device mounted on the exterior surface of the container. The heating element has a helically coiled portion with a generally U-shaped portion extending therefrom into thermal contact with a portion of the interior wall of the container directly confronting the thermal cut-out device. The helically coiled portion is positioned between the water inlet and the confronting wall portion and the water inlet is so positioned that the water moves in an unbaffled manner within the helically coiled portion toward the confronting wall portion thereby preventing "nuisance tripping" of the thermal cut-out.

Abstract: A heater plug comprising a heater coil connected to a terminal pin, said terminal pin maintained in gas-tight manner at least in part within and insulated from a plug shell, at least the surface of said heater coil formed by a metal or a base alloy of a metal of the platinum group said heater coil supported by heat resistant electrically insulating rod-like or tubular supporting body heater coil surrounded by a protective tube.The heater plug is useful as a starting aid for diesel engines and other internal combustion engines, especially those without spark ignitions.

Abstract: Apparatus for precisely regulating the paraffin temperature in an electrically heated tissue processor comprises a sensor which is detachably fastened to the tissue processor by a clamp so as to be partially immersed in the paraffin. A controller, coupled to the sensor, and coupled in series with the tissue processor heating element by a plug tap across a source of alternating current voltage, is responsive to the conduction state of the sensor and controls the delivery of power to the tissue processor heating element in accordance with the paraffin temperature as sensed by the sensor.

Abstract: The present invention relates to a heating element usable in particular in aquaria, characterized in that it is constituted by an electrical element proper, coated with a moldable and waterproof heat-conducting material, such as a resin preferably, which can be shaped by known methods.

Abstract: An elongated heater unit including an elongated resistor helix, terminals connected to the ends of the helix, at least a first surrounding metallic sheath, powder insulation material disposed within the first sheath and spacing the resistor helix from the sheath. The sheath is provided with at least one indentation and/or groove extending along at least a portion of the length of the first sheath. The method for constructing the heater unit includes forming the indentation by means of a roll with a protrusion, by utilizing a mandrel, by utilizing a temperature sensitive member or by utilizing a reducing sheath.

Abstract: A starting aid for an internal combustion engine comprises a tubular extension in the end of which is a spirally wound electric heating element. The extension is secured to a body which in use is located in a bore in the cylinder head of the engine so that at least part of the extension extends into a combustion chamber of the engine. The extension mounts a sleeve extending from the body towards the end of the extension and this is formed from a material having a high thermal conductivity. The sleeve acts to minimize the temperature attained by the extension when the aid is in use.

Abstract: The apparatus includes a housing enclosing a boiler in the lower portion and a water-filled condenser in the upper portion with an insulated partition between them. The entry of boiler feed water is controlled by a float valve in the boiler, and steam from the boiler is conveyed through the partition and thus through a condenser coil substantially immersed in the water in the condenser.

Abstract: A small ignition device comprising a string-like silicon carbide heating element extending between and joining in electrical connection respective silicon carbide rod-like terminals. The heating element is joined to the terminals by an electrically conductive silicon joint. The string-like element has all cross-sectional dimensions between 0.05 mm and 2 mm and has a resistivity of between 0.01.OMEGA..multidot.cm and 10.OMEGA..multidot.cm whereby said heating element is heated to between about 1000.degree. C. and 1300.degree. C. in about 1 to 4 seconds after an electric current is connected thereto.

Abstract: An aquarium heater includes a tubular glass housing provided with a temperature control circuit in the upper part thereof for switching on and off a heating element disposed in the lower part of the housing and comprising an elongated non-metallic support tube on which a helical resistance heating wire is wound. A temperature responsive bimetallic breaker switch enclosed in a metallic housing is coupled within a feed line to the heating wire and is located in the interior of the support tube slightly below the upper end thereof and extends within a number of turns of the heating wire, with length of the breaker switch representing a small fraction of the length of the support tube.

Abstract: An electric immersion heater of planar construction for use in industrial processes is constructed of a non-corrodable material and may be immersed at the side of a processing not containing corrosive liquids. The heater includes a thin planar polymeric support frame having side members with end sections extending beyond the end portions of the frame. An electrical resistance heating element wire shrouded with an integral layer of polymeric material is wound around the end portions of the frame to form a substantially flat heating element assembly. Imperforate polymeric cover plates are secured in spaced relationship to opposite faces of the heating element assembly by spacing and securing means engaging the side members of the frame. The peripheral edges of the cover plates are spaced apart to form a gap allowing for free flow of fluid through the heater between the plates throughout the entire extent of the heater.

Abstract: Heating device with a heating element of a material with positive temperature coefficient, of which two opposite sides are contacted by planar electrodes and give off the heat produced through the electrodes and planar sheets of insulating material covering the same to two heat-absorbing surfaces of a heater. The sheets of insulating material are coated on their side facing the heating element over a large area with a solder and are soldered to the electrodes. This insures permanent good heat transfer between the electrodes and the insulating material covering them. The firmly joining together of the heating element and the sheets of insulating material to form a structural unit facilitates the assembly, i.e., the installation of the heating device.

Abstract: An insulator for an electrical heating element includes an inner section and an outer section removably disposed thereabout. The electrical heating element is removably and loosely received within at least one of the sections. Several of these insulators can be used to make a new and improved electrical heating element assembly.

Abstract: A method for attaching and securing an apertured mounting bracket to a metal sheathed electric heating element received therethrough to insure firm mechanical support, prevention of relative axial motion, reliable electrical grounding, and ease of adaptation to automated assembly.

Abstract: The warm-up time of a glow plug starting device in a diesel engine is reduced by using as the material for the heat generating element in the glow plug a metallic resistance material whose resistance up to the starting temperature is less than two-thirds of the rated resistance of a conventional element. The starter circuit includes a detecting resistor in series with the heating element and a divider which divides the voltage across the heating element by the voltage across the detecting resistor in order to accurately determine the resistance and, thus, the temperature, of the heating element. The current to the element is interrupted and a self-holding starting relay is energized when the starting temperature has been obtained.

Abstract: Electric heating elements, particularly adapted for use in solder pots or in other uses wherein a substance is to be maintained in a molten or plastic condition, and commonly termed in such uses as over-the-side heaters. A conventional tubular heater is disposed within the central opening of a thick-wall metal pipe or tube, and the latter is swaged to reduce its cross-sectional size and thereby fit tightly about the tubular heater. Thereafter, the pipe and the heater therein, are bent in a pipe bender to any desired shape.

Abstract: An energy saving food serving system for rethermalization of the food and for delivery prepared meals to locations remote from the place of preparation, such as to patients to hospitals and nursing homes. The system includes a mobile cart having its own rechargeable power pack that is utilized to propel the cart. The cart has separate bays, each having a tier of racks for carrying individual food serving trays. Each tray has one or more thermally isolated heat transfer devices which are selectably energized when the tray is in place on a rack in the cart. Preferably, each tray has a pair of heaters referred to herein as plate and bowl heaters and adapted to be operated by control means in either a continuous mode of operation or a rethermalization mode of operation.

Abstract: An aquarium heater including a housing and a tube depending therefrom. An electric heating element is disposed in the bottom portion of the tube and a thermostatic control chassis is disposed in the upper portion of the tube. The control chassis includes two opposing housing sections matingly engaged in a nesting relationship to form a cylindrical housing unit which snugly fits into the tube and supports a bimetallic thermostatic switch together with associated circuitry and lead wires such that the thermostatic circuit elements are maintained securely positioned within the tube. The housing includes a gasket situated between a lip of the tube and the bottom wall of the housing, and a locking ring which clamps the rim of the tube in place. The tube is thereby held securely to the housing independently of the control chassis.

Abstract: A reservoir for an electric kettle is defined by a dome shaped shell and a planar inner bottom, which are fastened together mechanically having a room temperature vulcanized silicone rubber filler located therebetween to act as a seal. The shell is skirted by an inwardly projecting annular lip and has an inwardly projecting annular shoulder parallel with and spaced from the lip. The inner bottom is bounded by a downwardly extending annular flange, the top edge of which abuts the bead and the bottom edge of which engages the lip. The form of the kettle components permits the interior of the shell to be coated between the lip and shoulder with an annular coating of the silicone rubber whereat the inner bottom is readily snapped into position in the shell during assembly of the kettle.

Abstract: A method for differential thermal analysis and a furnace which is suitable for analytical measurements is heated by radiation. For this purpose, a radiation source whose radiation is absorbed by the furnace wall is arranged near to the furnace. The furnace is preferably formed as a hollow cylinder which surrounds the radiation source. An incandescent coil may, for example, be used as the radiation source.

Abstract: An electric heater for a foundry ladle wherein a frame is equipped with a descending electric heater operated and controlled to preserve the integrity of the electric heater.

Abstract: An improved electrical heating element for a high-temperature furnace including a support structure and an electrical-heating assembly. The support structure includes a plurality of thin, flat, non-conductive plates each having a plurality of spaced apertures therethrough and a plurality of non-conductive spacers smaller than the plates with one spacer interposed between each pair of adjacent plates. The electrical-heating assembly includes a plurality of elongated electrical conductors, preferably U-shaped, each leg extending through one aperture in each plate radially outwardly of the spacers. The conductors are supported by and extend between the plates and the ends of the conductors are interconnected so that the conductors as interconnected define a single tortuous electrical path radially outwardly of the spacers. The .[.interconnection.]. .Iadd.interconnections .Iaddend.between the conductors maintain the support structure in assembly.